From 839973a485a7954e4696455119414256dbea361a Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Tue, 25 Feb 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-02-25

---
 gnot/devport.c | 13 +++++++++++++
 port/devroot.c |  8 ++++++--
 port/segment.c |  6 ++++--
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/gnot/devport.c b/gnot/devport.c
index 7c195cdd34d32a6c01e54fa4e32da67b20f5f419..b2b2aec66ea6ff9e42f5fd54ffc9f8cdc123efe8 100644
--- a/gnot/devport.c
+++ b/gnot/devport.c
@@ -8,13 +8,18 @@
 
 #include	"devtab.h"
 
+#define	ROMADDR	0x40000000
+#define	ROMSIZE	((256*1024)/8)
+
 enum {
 	Qdir,
 	Qdata,
+	Qrom
 };
 
 Dirtab portdir[]={
 	"data",		{Qdata},	0,	0666,
+	"rom",		{Qrom},	ROMSIZE,	0444,
 };
 
 #define	NPORT	(sizeof portdir/sizeof(Dirtab))
@@ -132,6 +137,14 @@ portread(Chan *c, char *a, long n, ulong offset)
 		}
 		P_qunlock(s);
 		break;
+	case Qrom:
+		if(offset >= ROMSIZE)
+			return 0;
+		if(offset+n > ROMSIZE)
+			n = ROMSIZE - offset;
+		memmove(a, ((char*)ROMADDR)+offset, n);
+		return n;
+		break;
 	default:
 		panic("portread");
 	}
diff --git a/port/devroot.c b/port/devroot.c
index c22dc50965855814ec71cf6335d39c9176d0618d..1050768b9bfd2f0d5537530162e17a269d02ddc1 100644
--- a/port/devroot.c
+++ b/port/devroot.c
@@ -45,12 +45,14 @@ int	nroot;
 int
 rootgen(Chan *c, Dirtab *tab, int ntab, int i, Dir *dp)
 {
-	if(tab==0 || i>=ntab)
+	if(i >= nroot)
 		return -1;
+
 	if(i < NROOT)
-		tab += i;
+		tab = &rootdir[i];
 	else
 		tab = rootmap[i - NROOT];
+
 	devdir(c, tab->qid, tab->name, tab->length, eve, tab->perm, dp);
 	return 1;
 }
@@ -92,6 +94,8 @@ rootwalk(Chan *c, char *name)
 		c->qid.path = Qdir|CHDIR;
 		return 1;
 	}
+	if((c->qid.path & ~CHDIR) != Qdir)
+		error(Enonexist);
 	return devwalk(c, name, rootdir, nroot, rootgen);
 }
 
diff --git a/port/segment.c b/port/segment.c
index e7459d9f1fed502f4679556d3bd2fe32eb810bfe..ba4c7b0c2a46164e17057592ba0021110b42c935 100644
--- a/port/segment.c
+++ b/port/segment.c
@@ -274,7 +274,9 @@ imagereclaim(void)
 	for(;;) {
 		lock(&palloc);
 		for(p = palloc.head; p; p = p->next)
-			if(p->image && p->ref == 0 && p->image != &swapimage)
+			if(p->image)
+			if(p->ref == 0)
+			if(p->image != &swapimage)
 				break;
 
 		unlock(&palloc);
@@ -282,7 +284,7 @@ imagereclaim(void)
 			break;
 
 		lockpage(p);
-		if(p->ref == 0 && p->image != &swapimage)
+		if(p->ref == 0)
 			uncachepage(p);
 		unlockpage(p);
 	}